Combined lamp and switch unit for portable caseless flashlights



W. C. THOMPSON COMBINED LAMP AND SWITCH UNIT FOR PORTABL March 31, 1970 CASELESS FLASHLIGHTS Filed Deo.

3 U @um /NVENTOR WILUAM C THomPsoN ATTORNEY United States Patent Oce 3,504,170. Patented Mar. 31, 1970 U.S. Cl. 240-10.61 7 Claims ABSTRACT OF THE DISCLOSURE A combined flashlight lamp and switch unit capable of being rigidly attached to dry cell units. The dry cell unit may be replaced when it becomes exhausted. The lamp and switch unit has an open ended tubular body of electrical insulating material. A reflector of non-conducting material provided with a central opening is supported in the body member. A transparent cover closes the front end of the reflector. A metal collar is fixed in the opening of the reflector. A contact member receives the inner end of the reflector and is secured to the metal collar. The contact member has an insulating battery-attaching collar provided with screw threads for securing the ilashlight lamp and switch unit to a dry cell unit. A cup shaped lamp holder of electrically insulating material has a contact sleeve engaging the metal collar to secure the lamp holder to the reflector. A spring contact is mounted within the lamp holder for engagement with the positive electrode of a dry cell unit. A switch member is mounted in the body for opening and closing the lamp circuit.

My invention relates generally to a portable caseless dry battery electric lamp of the type disclosed and claimed in my United States Patent No. 3,332,805, issued July 25, 1967 and providing a plurality of dry cells which are of identical construction and are adapted to be detachably connected end to end in electrical series to form a rigid handle dispensing with the conventional case of metal or plastic and co-acting with a permanent lamp and switch unit to form the flashlight.

The primary object of my present invention is to provide a permanent unitary structure embodying a lamp and a switch for controlling the supply of current to the lamp from the cells when detachably connected to the unit, with the unit being structurally characterized to adequately protect the lamp against premature failure or breakage should the flashlight be dropped or roughly handled, thus prolonging the useful life of the lamp regardless of the severity of the service to which the flashlight is subjected.

Another object of my invention is to provide a lamp and switch unit of the above described character in which the transparent breakable protecting cover closing the front of the reflector of the unit is mounted to completely seal the reflector and lamp against foreign matter in a manner to be fully protected against breakage from such shocks as the flashlight is subjected to in service.

A further object of my invention is to provide a lamp and switch unit embodying means rendering the lamp accessible for removal from the unit and a new lamp substituted with the utmost ease and dispatch, with the unit having means to insure a highly eflicient electrical connection of the lamp and switch to the positive and negative electrodes of a cell when the unit is attached thereto, all in a manner to insure a structually strong and rigid detachable connection of the cell to the unit.

With these and other objects in view, my invention resides in the combinations, arrangements and functional relationships of elements as set forth in the following specification and particularly pointed out in the appended claims.

In the accompanying drawings,

FIGURE 1 is a longitudinal axis sectional view of a lamp and switch unit embodying my invention attached to one of a plurality of cells detachably secured together in electrical series to form a caseless flashlight;

FIGURE 2 is a fragmentary view in elevation partly broken away to show interior construction and looking in the direction of the arrow 2;

FIGURE 3 is a transverse sectional View taken on the line 3-3 of FIGURE l; and

FIGURE 4 is a plan View of a spring contact element with which the metal shell of the lamp is associated to protect the lamp against damage from shocks to which the flashlight is subjected.

Referring specifically to the drawings, my invention in its illustrated embodiment comprises a unit U composed of an open ended tubular body 10 of plastic or other electrical insulating material flared at one end which is slightly reduced in diameter to form an annular shoulder 11 and external screw threads 12. A reflector 14 of plastic is coated internally with a suitable non-conducting reflecting surface 15 and is provided with an outwardly projecting annular flange 16 seating against the outer end of the body 10. A lug or key 17 projects axially from the flange 16 and seats in a recess 1-8 in the body 10 to lock the reflector against turning relative to the body. The reflector is provided at its outer end with an internal annular shoulder 19 on which seated an annular U gasket 20 of rubber or other suitable yieldable material in which is mounted a transparent cover 21 of glass or other breakable material in the form of a disk closing the front of the reflector.

A retaining ring 25 of plastic is provided with internal screw threads 26 by which the ring is screwed onto the threads 12 of the body 10 until an annular shoulder 27 of the ring 25 seats against the outer end of the reflector 14 and contacts the gasket 20 without stressingthe latter, to the end that the cover 21 will be yieldingly mounted by the gasket so as to be fully protected against breakage.

The inner end of the reflector 14 is provided with a central opening in which is crimped or otherwise secured a metal collar 30 having internal screw threads 31 and external screw threads 32. A cup-shaped lamp holder 33 of plastic of other non-conducting material is provided at its inner end with an externally screw threaded contact sleeve 35 of metal which is screwed into the threads 31 of the collar 30 with the conventional flange 36 of the base or negative electrode 37 of a lamp 38 yieldingly supported between a gasket 39 of rubber or other suitable material and a spring metal contact ring 40 which is secured by crimping or indenting under the sleeve to become a permanent part of the sleeve.

The base 37 of the lamp 38 extends into the lamp holder 33 and is mounted in a liner 41 of resilient rubber or other suitable material so that the lamp will be cushioned against damage and premature failure. A spring contact 42 of generally U shape is`mounted in the holder 33 in rm electrical contact with the center contact or positive electrode 43 of the lamp 38 when the holder is screwed tightly into the collar 30.

A contact member 45 in the form of a disk having a peripheral ange 46 has a sleeve 47 of reduced diameter molded into a plastic battery-attaching collar 48 to form a unitary structure. The sleeve 47 has internal screw threads 49 by which the member 45 is screwed tightly onto the external screw threads 32 of the collar 30. after which the member 45 is indented at one or more points 50 into the inner end of the deector 14 to rigidly lock the' member to the reflector so as to be permanently secured to the latter.

When the parts of the unit U are assembled as shown in FIGUREI 1, the ange 46 of the member 45 engages a spring contact of a switch S and extends through an opening in the side wall of the body 10. A second Contact 56 of the switch extends into a groove around the body and forms part of a contact ring 57 of U- shaped cross section pressed around the inner end of the body 10. A bridging contact 58 of the switch S in the form of a bowed leaf spring with curled ends is mounted in a recess 59 of a plastic actuating member 60 by means of a pin 61.

The actuating member 60 is mounted in the body 10 or reciprocating movement between a stop shoulder 62 on the body and a stop pin 63 driven into the body, by means of runners 64 on the member slidable in guideways 65 on the body. In the one extreme and open position of the switch shown in FIGURE l, the bridging contact 58 is spaced from the switch contact S5 and engages 'the switch Contact 56, in which position the switch is releasably retained by seating of the bridging contact in a depression 66 in the contact 56. In the other and closed position of the switch, the bridging contact 58 remains in engagement with the contact 56 and engages the contact 55. A second depression 67 in the contact 56 in which the bridging contact seats, releasably retains the switch in closed position.

For the purpose of this invention, it will suiiice to state that each one of a plurality of cells C and C' composing the battery B, is constructed at one end to receive external threads 68 on the battery-attaching collar 48 of the unit U to secure the unit to the cell. The pitch of the threads 68 is different and preferably coarser than that of tbe threads 31 and 32 of the collar 30 so as to prevent unintentional unscrewing movement of the lamp holder 33 when the unit is being detached from the cell.

As shown in FIGURE l, the cell C is provided with active filler material 70 in a zinc cup 71 enclosed in an insulating jacket 72 which in turn is enclosed in a metal shell 73 forming the negative electrode of the cell. The positive electrode of the cell is formed by a centrally located carbon 74 which projects from the sealed end of the cell into electrical engagement with a metal socket 75 over which the upper end of the jacket 72 is crimped. A metal attaching collar 76 is provided with internal screw threads 77 clamped between the jacket 72 and the crimped upper end of the metal shell 73 so as to be electrically insulated from the positive electrode and complete the assembly of the upper end of the cell.

The unit U is attached to the cell C by screwing the collar 48 of the unit into the collar 76 of the cell until the roughened annular face 78 of the contact spring 57 bears tightly against the upper end of the negative electrode formed by the metal shell 73 to provide a rigid and highly efficient electrical connection therebetween. As the collar 48 is screwed into the collar 76, the spring contact 42 is stressed into engagement `with the positive electrode of the cell formed by the socket 75 and the carbon 74.

With switch S is the open position shown, no current will flow from the battery to the lamp 38. However, upon closing the switch a current will ow through the circuit completed as follows:

From the positive carbon electrode 74 and socket 7S to the spring contact 42, center contact 43 of the lamp 38, lamp filament, `base 37 of the lamp, then through the contact ring 40, sleeve 35, collar 30 and sleeve 47, contact member 45, switch Contact 5S, bridging contact 53, and switch contact 56 to the negative electrodeforming shell 73 to complete the circuit and light the lamp.

To replace a burned out lamp, it is only necessary to unscrew the unit U from the cell C and then unscrew the lamp holder 33 from the reilector 14 to obtain access to the lamp. The lamp is withdrawn from the holder and a new lamp inserted, followed by screwing the holder into the reflector and attaching the cell to the unit.

I claim:

1. In a ashlight, a combined lamp and switch unit for dry cells comprising: an open ended tubular body of electrically insulating material; a reflector of non-conducting material provided at its inner end with a central opening and being supporter in said body; a transparent cover; means securing said cover to close the front of said reilector; means locking said rellector to said body against rotation relatively thereto; a metal collar fixed in said opening of the reilector and having internal and external screw threads; a contact member receiving the inner end of said reflector and having internal screw threads screwed onto said external screw threads of said metal collar; means locking said contact member to said reilector; said contact member having an electrically insulating battery-attaching collar provided with screw threads for detachably securing the unit to a dry cell; a cup shaped lamp holder of electrically insulating material adapted to receive the negative electrode-forming base of an electric lamp having an annular flange on the base; said holder having a metallic externally screw threaded contact sleeve screwed into said internal screw threads of said metal collar to secure said holder to the reflector; said holder having a spring contact adapted to engage the positive electrode of the cell to which the unit is attached; switch contacts mounted on said body with one contact engaging said contact member and a second contact adapted to engage the negative electrode-forming metal shell of the cell when the unit is attached to the cell; and an actuating member mounted for movement on said body and having means co-acting with said switch contacts to open or close a circuit therebetween, to thereby control the flow of current from the cell to the lamp.

2. The combination as set forth in claim 1 including a cushioning liner in said lamp holder in which the base of the lamp is yieldably supported to protect the lamp against damage from shocks to which the ashlight is subjected.

3. The combination as set forth in claim 1 including means adapted to co-act with the base ange of the lamp to yieldably support the lamp between said metal collar and said contact sleeve in electrical engagement with the latter.

4. The combination as set forth in claim 3 wherein said last means comprises a non-conducting gasket between said metal collar and the base ange of the lamp, and a spring metal contact ring between the base llange and said metal contact sleeve of the lamp holder.

5. The combination as set forth in claim 1 wherein said second switch contact includes a contact ring extending around said body for electrical engagement with the end of said shell of the cell when the unit is attached thereto.

6. The combination as set forth in claim 1 wherein said means for locking the reflector to said body comprises a recess in one thereof and a key on the other thereof received in said recess.

7. The combination as set forth in claim 1 wherein said reflector is provided with an annular seat for said transparent cover; a gasket of yieldable material bounding the peripheral portion of said cover and yieldably mounting the cover on said seat; and said cover securing means comprising a retaining ring screw threaded on said body to seat against an annular shoulder on the body and hold said gasket against axial displacement without stressing the gasket so as not to adversely affect its cushioning action in protecting said cover against breakage.

References Cited UNITED STATES PATENTS 3,065,340 11/1962 Mead et al 24U-41.5 3,067,324 12/1962 Thompson 24U-10.61 3,128,050 4/1964 Parker Z110-10.66 3,332,805 7/1967 Thompson 240-10.61 XR NORTON ANSHER, Primary Examiner U.S. C1. XR. 

